<!DOCTYPE html>
<html>

<head>
  <meta charset="UTF-8" />
  <title>demo</title>
  <!-- 引入Vue -->
  <script type="text/javascript" src="../../js/vue.js"></script>
</head>

<body>
  <!-- 准备好一个容器-->
  <div id="demo">
    姓: <input type="text" v-model="firstName" /><br>
    名: <input type="text" v-model="lastName" />
    <h2>全名:{{fullName}}</h2>
  </div>
</body>

<script type="text/javascript">
  // 创建Vue实例，得到ViewModel
  var vm = new Vue({
    el: '#demo',
    data() {
      return {
        firstName: '',
        lastName: ''
      }
    },
    // methods: {
    //   fullName() {
    //     return this.firstName.slice(0.1).toUpperCase() + this.firstName.slice(1) + ' ' + this.lastName;
    //   }
    // }
    computed: {
      fullName: {
        get() {
          return this.firstName.slice(0, 1).toUpperCase() + this.firstName.slice(1) + ' ' + this.lastName;
        },
        set() { },
      }
      // fullName() {
      //   return this.firstName.slice(0.1).toUpperCase() + this.firstName.slice(1) + ' ' + this.lastName;
      // }
    }
  })
</script>

</html>